The castrato was such a known quantity for centuries, and yet we know relatively little about this shockingly widespread practice. Even Charles Burney, the famous early music historian, tried to learn more about this nebulous singing tradition on his trips through Italy in the 18th century. Not surprisingly, he could find no one willing to admit that they knew anything about how castrati came to be who they were, and he was told in every city that it happened only in some other place. The theme of Andreas Scholl's latest CD is that all the arias on it were composed for one of the famous castrati of the 18th century, Francesco Bernardi, known as Il Senesino. The pieces are a mix of well-known and obscure. Surely not by coincidence, Scholl has laid down gorgeous renditions of two pieces from Handel's Rodelinda (1725), in which he will make his Metropolitan Opera debut this May. (The role of Bertarido, written for Senesino, was Scholl's operatic breakthrough, at Glyndebourne in 1998.)

Senesino was a celebrated alto castrato from Siena, and after singing for many years across Italy and Germany, Handel negotiated a contract for him to sing for the Royal Academy of Music in London, beginning with that company's second season in 1720. He performed with them for every season through June 1728, when the Royal Academy temporarily folded, during which period Handel composed or adapted 13 operatic roles for him. When the Roman-born cellist, composer, and poet Nicola Francesca Haym joined the Royal Academy as official librettist and Italian Secretary in 1722, he formed a very successful triumvirate with Handel and Senesino. Rodelinda (1725) -- for which Haym revised a libretto by Salvi -- was only one of their successes.

There are probably more famous countertenors making recordings and singing on opera stages around the world in this decade than in many previous to it. This is a voice that has finally come into its own, and Andreas Scholl is at the top of the game. As a boy chorister in a small but well-reputed church choir in his hometown, Scholl's speaking voice changed, but he continued to sing as a treble or alto. He went to study with René Jacobs in Basel, where he lives today, and a few memorable early performances catapulted him to fame. He even appeared as a singing monk in the film The Name of the Rose, with Sean Connery as Umberto Eco's famous monastic detective. His voice is well suited to the pieces composed for Senesino, whose range was rather narrow (up to D or E on the treble staff) and who, although capable of virtuosic melismatic passages, was reportedly strongest in long and sustained lines.

Beginning with Senesino's early career, we join him for his 1708 stage appearances in Venice, with two virtually unknown arias by Tommaso Albinoni, a contemporary of Vivaldi, from Astarto and Engelberta. "Stelle Ingrate" is a concise and pleasing fast-paced aria, and "Selvagge Armenita" is in a gentle triple meter with a sweet melody. Neither is particularly memorable. We know that Senesino appeared in Bologna in 1709 in Caldara's L'inimico generoso, and given how much I enjoyed Cecilia Bartoli's Caldara arias, I was disappointed that Scholl did not choose any pieces by Caldara. In 1713 and 1714, Senesino was back in Venice, performing in works by Lotti and others, and then in Naples in 1715 to 1716. The only aria by Alessandro Scarlatti on this CD, "Del ciel su sui giri" from Carlo Re Allemagna (1716), is a boisterous and heroic one. Scholl's artistic collaborators, the Accademia Bizantina led by Ottavio Dantone, generally play quite well, with the only exception being the imprecise horn playing on this track's lengthy ritornello.

The Dresden theater lured Senesino to their city in 1717, with an outrageous star salary of 7,000 thaler. For three seasons, he sang in several operas, including three by Antonio Lotti. Scholl has wisely chosen two examples, both among the better tracks on this CD, the lilting "Fosti caro" from Ascanio (1718) and "Discordi pensier" from Teofane (1719). In the latter, in a plaintive minor key, the vocal part is echoed beautifully by solo violin. It was in this opera that Handel first heard Senesino's voice, when he was sent to Dresden to attempt to engage him for the Royal Academy in London. In 1720, Dresden dismissed Senesino for one of the many tirades associated with this difficult singer: he refused to sing an aria assigned to him and tore up a score. His temperamental behavior immediately caused him to clash with Handel, who was not patient with artistic whims and who reportedly called him a "damned fool."

Handel put up with Senesino, however, because he was from the start well reviewed by press critics and audiences. All six Handel pieces on this CD are exquisite compositions in very good performances. In particular, the choice of three excerpts from Giulio Cesare (1724) is laudable. One review of this opera in London lauded Senesino's singing as "beyond all criticism." Handel crafted music for the "damned fool" that showcased his strongest vocal points, and Scholl gives us many of the same qualities, especially in the long crescendi and pure intonation of "Aure, deh, per pietà" and the accelerating pace of "Al lampo dell'armi." The final Handel piece, the gloriously long and already famous "Cara sposa" from Rinaldo (1731), dates from the second incarnation of the Royal Academy, for which Senesino returned to London. This was only two years before Handel finally called it quits with Senesino, unable to tolerate his vanity and tantrums any longer. The CD concludes with an aria from Porpora's Il Trionfo di Camilla (1740), which was the castrato's final public performance. The castrato voice usually sank in vocal range with age, and this aria seems to reflect that descent, emphasizing the lower part of the countertenor voice, normally the weakest, and Scholl is no exception.

The criticism being leveled at this CD, that it is lightweight and piles on the trend ofHandelariaCDs, is mitigated somewhat by the musicological value of the more obscure pieces, edited by Alessandro Borin for this CD. (I hope Decca made a legal arrangement for the payment of royalties to the editor.) In particular, the Lotti arias from the Dresden operas are good discoveries, although the work of Handel, at the height of his operatic powers in the 1720s and 30s, overshadows everything else. Andreas Scholl has a gorgeous line with pure and powerful notes, never shrill, at the top of Senesino's range and an absolutely clean melismatic mechanism, much less labored in sound than a voice like Cecilia Bartoli. However, Bartoli's selection of arias is of much greater interest, in terms of both music and scholarship. If you really want to accuse Scholl of being a lightweight, you should attack his previous CD, called Wayfaring Stranger, a set of folksongs with Orpheus Chamber Orchestra. The tag lines invented by the Decca PR machine? "Some new twists on a great tradition" and "not embarrassed by the magic." (An anonymous commenter, who corrected my misunderstanding of the packaging of this disc on the Decca Web site, says it's not bad.)